CSV Parsers

The CsvParser class is used to parse CSV into POJOs.

The class hierarchy for the builder of this parser is:

Context.BuilderMarshallingContextable.BuilderParser.BuilderReaderParser.BuilderCsvParser.Builder

Refer to the builder javadocs for configurable settings.

The following pre-configured parsers are provided for convenience:

CsvParserDEFAULT

Usage

// Parse a CSV string into a list of beans
String csv = "name,age\nAlice,30\nBob,25\n";
List<Person> people = CsvParser.DEFAULT.read(csv, List.class, Person.class);

// Parse into a list of maps
List<Map<String,String>> rows = CsvParser.DEFAULT.read(csv, List.class, Map.class);

// Parse into a single bean
String singleRow = "name,age\nAlice,30\n";
Person p = CsvParser.DEFAULT.read(singleRow, Person.class);

// Use the Csv marshaller for convenience
List<Person> people = Csv.to(csv, List.class, Person.class);

Supported Target Types

Target Type	Parsing Strategy
Collection<Bean> / Bean[]	Header row → property names; each data row → one bean.
Collection<Map> / Map[]	Header row → map keys; each data row → one map.
Collection<SimpleType> / SimpleType[]	value column; each row → one value coerced to element type.
Single Bean	Header row + one data row → one bean.
Single Map	Header row + one data row → one map.
Object	Returns a JsonList of JsonMap entries (all values as strings).

Type Coercion

Cell values are strings in CSV. The parser automatically coerces them to the target property/element type using the same type conversion machinery used by all Juneau parsers:

• Primitive types and their wrappers (int, long, double, boolean, etc.)
• String
• Enum types (by name)
• BigDecimal, BigInteger
• Date/time types (Date, Calendar, Temporal subtypes) — as ISO 8601 strings
• Duration — as ISO 8601 duration strings (e.g. PT1H30M)
• Any type whose ClassMeta supports convertToType(String)

Null Handling

The unquoted literal string null in a CSV cell is parsed as Java null. A quoted "null" cell is parsed as the Java String "null".

Quoted Fields

The parser handles all RFC 4180 quoted field constructs:

• "hello, world" → hello, world (comma inside quoted field)
• "line1\nline2" → line1\nline2 (newline inside quoted field)
• "say ""hi""" → say "hi" (doubled quotes → single quote)

Unknown Properties

By default, CSV columns that do not match any bean property are silently ignored (the ignoreUnknownBeanProperties parser setting applies). To throw on unknown properties, configure the parser:

CsvParser p = CsvParser.create()
    .disableIgnoreMissingSetters()
    .build();

Swaps

Object swaps registered on the parser are applied during cell value conversion:

CsvParser p = CsvParser.create().swaps(DateSwap.class).build();
List<Event> events = p.read(csv, List.class, Event.class);

Media Type

CsvParser consumes input of media type text/csv.